Fear of Communist infiltration swept the nation after World War II, and nothing characterized the government's paranoid reach into citizens' lives more than the loyalty oaths that thousands of Americans had to sign.

In the summer of 1950, the University of California vigorously enforced a state law requiring public employees to sign such an oath, and more than 11,000 UC employees did so rather than risk losing their jobs.

Charles Muscatine, a recently hired assistant professor of English, said no. He was among 31 UC Berkeley professors who refused to sign.

Won in court

Their refusal - and subsequent legal victory - is seen as helping to lay the groundwork for the Free Speech Movement that took hold on campus a decade later.

Professor Muscatine went on to become perhaps the most influential Chaucerian scholar of his generation, with his first book, "Chaucer and the French Tradition," transforming the study of Chaucer's poetry.

"I had been insisting to the kids that you stick to your guns and tell it the way you see it, and you think for yourself and you express things for yourself," he explained, years after the loyalty oath controversy. "I felt that I couldn't really justify teaching students if I weren't behaving the same way. So I simply couldn't sign the oath."

He saw it as a violation not only of academic freedom, but of the oath to the U.S. Constitution he had already taken when he entered the Navy during World War II. A lieutenant, he landed at Omaha Beach during the D-Day invasion of Normandy.

Many UC employees believed they had to sign the loyalty oath because they had families to support, or a mortgage. Professor Muscatine had both. Yet he had no choice, said his daughter, Lissa Muscatine, a speech writer for Secretary of State Hillary Rodham Clinton.

"For him, fighting against Hitler in World War II to define democratic principles was the same as standing up for democratic principles by not signing the loyalty oath," she said.

Born on Nov. 28, 1920, the son of Russian Jewish immigrants, the professor grew up in Trenton, N.J. Knowing little about colleges, he applied to just one, which he'd heard was pretty good. Yale admitted him at age 16.

He took his B.A. there in 1941, and his master's a year later. He returned to Yale after the war, earning his doctorate in 1948.

Coming to Berkeley

He joined the faculty at UC Berkeley the next year, and he and his wife, Doris, bought a house. They lived there with their new baby, Jeff.

"The prospect of being fired, particularly if you don't have tenure, is a serious one," Professor Muscatine later recalled. "If you got a reputation for being a Communist sympathizer, which none of us was, you couldn't get a job anywhere. So it was a very serious situation fraught with danger for yourself and your family."

UC Berkeley fired the young scholar and his colleagues in 1950. He eventually found a job at Wesleyan University in Connecticut, where he remained for two years.

At the same time, he was among the faculty members who sued over the loyalty oath. In 1954, the California Supreme Court rescinded the requirement, and the professor returned to UC Berkeley.

East Bay attorney Peter Francke, who graduated from UC Berkeley in 1958, recalled that Professor Muscatine was among the few faculty members who encouraged students to stand up for their beliefs.

"At a time when the campus administration was doing things to keep students away from issues of social importance, he was different," Francke said. He was faculty adviser to campus groups, including the American Civil Liberties Union.

The professor also grew in scholarly stature, and impressed colleagues by flying a small plane to conferences. They called the dashing professor the Cary Grant of his field, said former student Michaela Grudin, also a scholar of medieval literature.

"He knew Anglo Saxon - also called Old English - and he read in medieval French," Grudin said.

In addition to publishing on Chaucer, Professor Muscatine wrote widely about education reform and the importance of clear, coherent curriculum at the college level. His most recent book, "Fixing College Education: A New Curriculum for the Twenty-First Century," was published in July.

Not surprisingly, he practiced what he preached.

A student review of his teaching from the late 1950s says that the "only fault in the discussion was the occasional dullness of students."

He taught a freshman English class each year, and recently tutored at a local library.

"He really believed in training young people to have critical minds," his daughter said.

In addition to his daughter, Lissa of Bethesda, Md., and son, Jeff of Mountain View, Professor Muscatine is survived by sister-in-law Draselle Muscatine of Napa, six nephews, one niece and six grandchildren.